Dual loop coriolis effect mass flowmeter

ABSTRACT

An apparatus for measuring the flow rate of a fluid flowing through a minimal flow pipeline with a Coriolis effect mass flowmeter. The flowmeter has a single flow tube with two loops. The loops are connected by a cross-over section. A driver oscillates the loops and the phase difference between the ends of the loops is measured. The measured phase difference is then used to find the flow rate of the fluid. The flow tube is fixably attached to an anchor which is, in turn, attached to a housing. The anchor separates the vibrating, dynamic portion of the flowmeter from the non-vibrating portion of the flowmeter.

CROSS REFERENCED/RELATED APPLICATIONS

This application is a continuation application of pending application08/814,203 filed on Mar. 11, 1997 which is hereby incorporated byreference as if set forth in its entirety below.

FIELD OF THE INVENTION

This invention relates to an apparatus for using a Coriolis massflowmeter with a serial, dual loop, flow tube for measuring the flowrate of a fluid through a pipeline. More particularly, the inventionrelates to the element used to connect the loops of the flow tube. Stillmore particularly, the invention relates to an anchor which connects aflow tube to a flow tube housing.

Problem

It is known to use Coriolis effect mass flowmeters to measure mass flowand other information of materials flowing through a pipeline asdisclosed in U.S. Pat. Nos. 4,491,025 issued to J. E. Smith, et al. ofJan. 1, 1985 and Re. 31,450 to J. E. Smith of Feb. 11, 1982. Theseflowmeters have one or more flow tubes of a curved configuration. Eachflow tube configuration in a Coriolis mass flowmeter has a set ofnatural vibration modes, which may be of a simple bending torsional, orcoupled type. Each flow tube is driven to oscillate at resonance in oneof these natural modes. The natural vibration modes of the vibrating,material filled system are defined in part by the combined mass of theflow tubes and the material within the flow tubes. Material flows intothe flowmeter from a connected pipeline on the inlet side of theflowmeter. The material is then directed through the flow tube or flowtubes and exits the flowmeter to a pipeline connected on the outletside.

A driver applies force to oscillate the flow tube. When there is no flowthrough the flowmeter, all points along a flow tube oscillate with anidentical phase. As the material begins to flow, Coriolis accelerationscause each point along the flow tube to have a different phase withrespect to other points along the flow tube. The phase on the inlet sideof the flow tube lags the driver, while the phase on the outlet sideleads the driver. Pickoff sensors are placed on the flow tube to producesinusoidal signals representative of the motion of the flow tube. Thephase difference between the two pickoff sensor signals is proportionalto the mass flow rate of the material flowing through the flow tube orflow tubes.

Material flow though a flow tube creates only a slight phase differenceon the order of several degrees between the inlet and outlet ends of anoscillating flow tube. When expressed in terms of a time differencemeasurement, the phase difference induced by material flow is on theorder of tens of microseconds down to nanoseconds. Typically, acommercial flow rate measurement should have an error of less the 1%.Therefore, a Coriolis flowmeter must be uniquely designed to accuratelymeasure these slight phase differences.

It is known to use a single loop, serial path flow tube to measure therate of fluid flowing through a pipeline. However, the single loop,serial flow tube design has a disadvantage in that it is inherentlyunbalanced. A single loop, serial flow Coriolis flowmeter has a singlecurved tube or loop extending in cantilever fashion from a solid mount.Dual loop Coriolis flowmeters are balanced. A dual loop Coriolisflowmeter has two parallel, curved tubes or loops extending from a solidmount. The parallel flow tubes are driven to oscillate in opposition toone another with the vibrating force of one flow tube canceling out thevibration force of the other flow tube. The result is that in a properlyconstructed dual loop Coriolis flowmeter there are no flowmeter inducedvibrations at the points of attachment between the flowmeter and thepipeline. This is called a “balanced” flowmeter. The absence ofvibrations allows dual looped Coriolis flowmeter to be attached freestanding to a pipeline. A single loop, serial path Coriolis flowmetermust be secured firmly to a support against which the flow tube canvibrate. The use of a support renders the use of a single loop, serialflow tube design impractical in most industrial applications because theserial flow tube requires that the pipeline be near an object that couldbe used as a support. Therefore, the dual loop flowmeter designs aredesirable.

It is a particular problem to measure minimal flow rates of materialsflowing through a pipeline. A mass flow rate through a pipeline of lessthan or substantially equal to 4 lbs. per minute is considered minimalfor commercial applications. A Coriolis mass flowmeter measuring suchsmall flow rates must be formed of relatively small components includingtubes and manifolds. These relatively small components present a varietyof challenges in the manufacturing process including but not limited todifficult welding processes.

One solution for measuring minimal flow rates has been to use a singleloop, serial flow tube Coriolis effect mass flowmeter. Single loop,serial flow tube Coriolis flowmeters have certain advantages. The flowtube has a larger diameter which reduces pressure drop across theflowmeter. No manifold is necessary to split the flow into two tubes.The larger flow tube is easier to draw and weld. There are also otheradvantages. The problem is that single loop, serial flow tube flowmeterscannot be mounted free standing into the pipeline since they are notbalanced flowmeters.

Dual loop, parallel flow tube flowmeters can be mounted freestandinginto the pipeline. However, the small size necessary for measuringminimal flow rates creates design and manufacture problems for use ofthe dual loop, parallel flow tube design. These problems limit theindustrial applications of dual loop, dual tube Coriolis flowmeters formeasuring minimal flow rates.

A particular problem with dual loop, parallel flow tube design is that amanifold must be used to direct the flow entering the inlet end of theflowmeter in order to divide the flow so that it enters the two flowtubes. It is difficult to produce a manifold, by casting or otherwise,in the small dimensions necessary to measure a minimal flow rate. Also,the manifold increases pressure drop across the flowmeter. Further, theflow tubes must be welded or brazed onto the manifold it is difficulttoo weld very thin walled tubing. The welds and joints do not providethe smooth surface needed for sanitary applications of the flowmeter.Sanitary applications demand a continuous, smooth flow tube surface thatdoes not promote adhesion of material to the walls of the flow tube.Further, the additional welds there are necessary reduce themanufacturing yield. Therefore, the use of a manifold is not desired inflowmeters designed for measuring minimal flow rates.

The smaller diameters of the dual flow tubes make the tubes more proneto plugging. The smaller diameter is needed to assure a sufficient flowrate through the i flow tubes. Material is more likely to plug the flowpath through these flow tubes because smaller particles in the materialcan obstruct the smaller flow path. These obstructions can causeinaccurate readings of the flow rate and breakage of the flow tube.Therefore, the dual flow tube design does not offer a satisfactorysolution for measuring minimal flow rates.

A further problem is that sometimes a Coriolis flowmeter is used tomeasure flow through a pipeline where the flowing material ispressurized. If a flow tube cracks, the pressured material will rapidlyspray from the highly pressurized flow tube to the outside surroundingswhich have a lower pressure than the flow tube. The pressurized materialspraying from the flow tube can damage the pipeline or surroundingstructures.

Solution

The above and other problems are solved by the apparatus of the presentinvention that comprises a dual loop, serial path flow tube. Each of theloops is oriented in a plane parallel to the plane containing the otherloop. The flow tube is enclosed in a housing to which the flow tube isconnected through an anchor. The housing can be configured to containthe leakage of pressurized materials from a break in the flow tube.These advantages allow the present invention to be used to measure theflow rates, including minimal flow rates, of material flowing throughthe pipeline.

In the present invention, the dual loops in the serial flow tube areconnected by a crossover section. The outlet end of the first loopconnects to an inlet end of the crossover section in the planecontaining the first loop. The inlet end of the second loop connects toan outlet end of the crossover section in the plane of the second loop.The crossover section of the flow tube allows the present invention tohave the advantages of both serial and parallel flow tube designs formeasuring minimal flow rates.

The present invention has a serial flow tube. Serial flow tube andparallel flow tube flowmeters each have advantages and disadvantages.For the same tube parameters, i.e. inside tube diameter, tube wallthickness, and tube geometry, an oscillating serial flow tube generatesmore Coriolis force than an oscillating parallel flow tube since all theflow passes through each portion of a serial flow tube instead of onlyhalf of the flow passing through each portion of a parallel flow tube.

The disadvantage of a serial flow tube is that the pressure drop througha serial flow tube is higher than for a parallel flow tube with the sametube parameters. To reduce pressure drop, a sensor with a serial flowtube typically uses a larger diameter and proportionally thicker flowtube wall to achieve substantially the same pressure drop of a parallelflow tube flowmeter. Therefore, serial path Coriolis flowmeters areinherently larger than parallel path flowmeters. Generally this is adisadvantage for Coriolis flowmeters. However, for minimal flow ratesensors it is an advantage. A flow tube with a greater diameter reducesthe probability of particles plugging the flow tube. The joining, bywelding or brazing, of a relatively larger diameter, heavier wall flowtubs make the flowmeter design of the present invention easier toproduce and better suited for sanitary applications. Therefore theflowmeter of the present invention can be used for industrialapplications in which a typical dual loop, parallel flow flowmetercannot be used.

The present invention is also an improvement over the dual loop,parallel flow tube flowmeters because the present invention does notneed a manifold. Manifolds are needed in dual flow tube designs todivide the flow entering the flowmeter into the two flow tubes. Sincethe present invention has a serial flow tube, a manifold is not neededto divide the flow. Thus, the flow tube of the present invention iseasier to weld as there are fewer welds.

The two loops of the flow tube of the present invention are oscillatedin opposition to one another. Vibrations caused by the oscillation ofthe loops are canceled out and do not affect the ends of the flowmeter.Therefore, the flowmeter of the present invention is balanced and doesnot have to be attached to a support. Thus, the flowmeter of the presentinvention may be attached freestanding in a pipeline without mountingthe flowmeter to a support.

The flow tube of the present invention is secured, near the crossoversection, by an anchor. The anchor is the solid mounting from which thedual loops of the flow tube extend in cantilever fashion. The anchor isfixed to a flowmeter housing. The inlet and outlet of the flow tube areconnected to the housing through an adapter which transitions the fluidfrom the flow tube to a process connection. The process connections areflanges or the like for connecting the flow tube to the processpipeline. Therefore the flow tube, anchor, and housing share a commonphysical reference. The housing can be designed to contain the leakageof a pressurized fluid in the case breakage of the flow tube. The anchorconnected to the housing and flow tube holds the flow tube securely inplace with enough room to oscillate freely inside the housing. Theanchor is used to attach the flow tube to the housing to minimize theeffect of distortions of the flow tube that would be caused if the flowtube were attached directly to the housing with welds. Also the anchordecouples the vibrating portion of the flowmeter, above the anchor, fromthe non-vibrating portion of the flowmeter where the flowmeter attachesto the pipeline.

The inlet and outlet portions of the flow tube of the present inventioncan be formed to any desirable configuration. For example the inlet andoutlet portions of the flow tube can be formed in-line with each otheror the meter can be made self-draining by forming them in a spiral,off-set configuration.

The modular design of the flowmeter of the present invention makes itrelatively easy for the designer to make changes to the wettedcomponents of the flow tube. Since the fluid only contacts the flow tubeand the adapters, the housing and anchor can be used with flow tubes andadapters of different materials without necessarily making any furtherdesign changes.

The apparatus of the present invention has the above described and otheradvantages in measuring the flow rate of material flowing throughpipelines. Unlike traditional Coriolis flowmeters, the present inventionhas a serial, balanced flow tube. A crossover section in the flow tubeconnects two loops in the flow tube. The configuration of the serialflow tube allows the present invention to behave like a dual flow tubeflowmeter, while having serial flow tube characteristics. The anchor andhousing configuration provide support for the flow tube and minimizedistortion of the flow tube.

DESCRIPTION OF THE DRAWINGS

FIG. 1 discloses a flow tube with a crossover section of the presentinvention;

FIG. 2 discloses a flow tube with the shape of the preferred embodimentof the invention;

FIG. 3 discloses a top-side view the flow tube of the present invention;

FIG. 4 discloses a top-side view of the complete flowmeter of thepresent invention with the top housing removed to expose the interior,

FIG. 5 discloses a flow tube of the present invention with b-shapedloops;

FIG. 6 discloses a flow tube of the invention with circular loops;

FIG. 7 discloses an assembly view of the preferred embodiment of theCoriolis flowmeter of the present invention;

FIG. 8 is a process flow chart illustrating the steps for manufacturinga flowmeter according to the present invention;

FIG. 9 depicts a brace bar half; and

FIG. 10 depicts a portion of two flow tube loops and interconnectingbrace bar halves.

DETAILED DESCRIPTION

Flow Tube Geometry—FIGS. 1-4

A basic embodiment of the flow tube 101 of the present invention isillustrated in FIG. 1. Inlet 103 of serial flow tube 101 attaches to apipeline and receives a flowing material from the pipeline. Outlet 104attaches to the pipeline to return the flowing material to the pipeline.Serial flow tube 101 has two loops 151 and 152. Crossover section 115joins loops 151 and 152 to form one continuous flow tube 101.

FIG. 3 illustrates a top view of flow tube 101. Elements common betweenany of the FIGS. are referenced by common reference numerals. Flow tubeloop 151 is oriented in plane F2 and flow tube loop 152 is oriented inplane F1. Planes F1 and F2 are parallel. Crossover section 115 has afirst end in plane F2, where it is attached to loop 151. The middlesection of crossover section 115 traverses from plane F2 to plane F1.Crossover section 115 then has a second end connected to loop 152 inplane F1. One continuous flow tube 101 is produced by the connection ofloops 151 and 152 by crossover section 115.

Crossover section 115 is an important element of continuous flow tube101. Crossover section 115 eliminates the need for the manifold byforming the flow tube itself to conduct the fluid from loop 151 to 152.Serial flow tube 101 is continuous and provides a smooth tube surfacerequired for sanitary applications.

A drive coil 131 is mounted at a midpoint region of flow tube loops 151and 152 to oscillate loops 151 and 152 in opposition to each other. Leftpick-off sensor 132 and right pick-off sensor 133 are mounted in therespective corners of the top sections of flow tube loops 151 and 152.Pickoff sensors 132 and 133 sense the relative velocity of flow tubeloops 151 and 152 during oscillations.

In the embodiment of FIG. 1, loops 151 and 152 are substantiallytriangular shaped. Loops 151 and 152 of the flow tube contain bends 111,112, 121, and 122. Each of the bends 111, 112, 121, and 122 issubstantially 135-degrees. Straight sections 116, 117, 118, 126, 127,and 128 connect to bends 111, 112, and 121, and 122. Straight sections116 and 118 of loop 151 and straight sections 128 and 128 of loop 152are nonparallel and aligned substantially 90 degrees from each otheralong their longitudinal axis. Crossover section 115 connects straightsection 118 on the right side of loop 151 to straight section 126 on theleft side of loop 152. The complex bend of crossover section 115connects loops 151 and loops 152 so that material flows in the samedirection through each loop.

FIG. 2 illustrates the shape of the serial flow tube 101 of thepreferred embodiment of the present invention. Flow tube 101 has all ofthe elements depicted in FIG. 1 with the additional elements of inletbend 201 and outlet bend 202. Inlet 103 and outlet 104 are planar with apipeline (not shown) and are not coplanar with either plane F1 or F2.(See FIG. 3) Inlet bend 201 attaches inlet 103 with loop 151 by crossingfrom inlet 103 to plane F1 and connecting to section 118. An outlet bend202 joins outlet 104 and loop 152 by crossing from outlet 104 to planeF2 and connecting with section 128. The inlet and outlet bends allowCoriolis flowmeter 101 to be attached to the pipeline while the twoloops are not planar with the pipeline.

FIG. 4 illustrates a flowmeter 400 including flow tube 101, anchor 401and housing base 450. Flow tube 101 is fixably attached to anchor 401 ata location near cross-over section 115 of flow tube 101. Flow tube loops151-152 extend from anchor 401 on one side of anchor 401. Cross-oversection 115 extends from anchor 401 on an opposite side of anchor 401.One way to attach loops 151-152 to anchor 401 is with blocks 411 and412. Anchor 401 is formed with depressions corresponding to the outerdiameter of flow tube 101. Likewise, blocks 411 and 412 are formed withcorresponding depressions. During assembly, anchor 401, blocks 411-412and flow tube 101 are brazed together to form a fixed, solid attachmentbetween flow tube 101 and anchor 401 at the interfaces between anchor401 and blocks 411-412. Anchor 401 is then welded to housing base 450using bosses (not shown) corresponding to and oppositely arranged frombosses 413-414. During operation of flowmeter 400, the non-vibratingportion of flow tube 101 extends from face 432 of anchor 401 and thevibrating portion of flow tube 101 extends from the opposite face ofanchor 401.

Inlet 103 of flow tube 101 is connected to adapter 402 with, preferably,an orbital weld at location 421. Outlet 104 of flow tube 101 isconnected to adapter 403 with preferably an orbital weld at location422. Since inlet 103 and outlet 104 are not part of the vibrating,dynamic portion of the flowmeter they can be arranged in anyconfiguration. For example, inlet 103 and outlet 104 can be arranged sothat planes F1-F2, with reference to FIG. 3, are perpendicular to thepipeline to which the flowmeter is connected. Another alternative is toarrange inlet 103 and outlet 104 so that flowmeter 400 is self-draining.Driver 131 and pickoff sensors 132-133 are arranged, and operate, asdescribed with respect to FIG. 1. Brace bars 425-426 are fixablyattached between loops 151-152 of flow tube 101.

Brace Bars—FIGS. 9-10

FIGS. 9-10 depict the preferred embodiment of brace bars 425-426. Eachof brace bars 425-426 is comprised of two brace bar halves 900. Eachbrace bar half 900 has a body 901 and an overlap tab 903. In addition,each brace bar half 900 has a hole 902 through which flow tube 101passes. FIG. 10 depicts the manner in which two brace bar halves 900 areconnected to form a single brace bar 425 or 426. Brace bar half 900Ahaving body 901A and overlap tab 903A is positioned on flow tube loop151. Likewise, brace bar half 900B having body 901B and overlap tab 903Bis positioned on flow tube loop 152. Overlap tab 903A and overlap tab903B overlap one another and are tack-welded in the region of theiroverlap. This forms a solid, one piece brace bar between flow tube loops151 and 152. Brace bars 425-426 are each comprised from two brace barhalves 900, as just described.

Forming each brace bar 425-426 from two brace bar halves 900 allowssignificant flexibility in assembly of the flowmeter of the presentinvention. The brace bar halves 900 are threaded onto flow tube 101 atany time prior to the attachment of flow tube 101 to adapters 402-403.Flow tube 101 can be further processed before the brace bar half pairsare welded together to form complete, solid brace bars.

Flowmeter Assembly—FIGS. 7-8

FIG. 7 is an exploded view of the complete flowmeter 700 includinghousing cover 701, housing base 450 and the remaining components asdescribed below. Housing cover 701 has holes 721-722 which mate withbosses 414 and 413, respectively. Housing cover 701 also has holes724-723 through which bosses 703-704 extend.

Adapters 402-403 attach to flow tube 101 using preferably orbital weldsat points 421-422, Adaptor 403 has surface 727 that is welded to surface728 on housing base 450 and housing cover 701. Adaptor 402 has a similarsurface (not shown) that is welded to surface 729 on housing base 450.As described with respect to FIG. 9, brace bars 425-426 are each formedfrom two brace bar halves 900 which are welded to form a complete bracebar. Anchor 401 and anchor blocks 411-412 are brazed to flow tube 101 toform a solid attachment between flow tube 101 and anchor 401.Depressions 730 in blocks 411-412 and depressions 731 in anchor 401 areformed to cooperate with the outer diameter of tube loops 151-152.Anchor 401 has bottom bosses (not shown) which insert through holes725-726 in housing base 450. Anchor 401 is welded to housing bass 450where the bottom bosses pass through holes 725-726. Bosses 413-414 and703-704 are inserted through holes 722-721 and 723-724, respectively.Housing cover 701 and bosses 413-414 and 702-704 are yielded together.Finally, housing base 450 is welded to housing cover 701 around theentire circumference of the mating edge between housing base 450 andhousing cover 701.

Flow tube 101 is thereby coupled to the flowmeter housing andconsequently the pipeline (not shown) through anchor 401 and adapters402-403. Any stresses induced by the pipeline on flowmeter 700 are seenonly by the non-vibrating portion of flow tube 101 below anchor 401.Thus the vibrating, active measurement portion of flow tube 101 is noteffected by external forces, torques and vibrations. Anchor 401 ismassive enough that it experiences minimal distortion when welded tohousing base 450 and housing cover 701. This in turn means that flowtube 101 experiences minimal distortion as a result of the weldingoperations. Any distortion that does occur to flow tube 101 at leastoccurs equally to both loops 151-152 thereby minimizing any impact onthe measurement performance of flowmeter 700.

Housing base 450 and housing cover 701 can be formed of thick enoughmaterial such that flowmeter 700 is capable of withstanding significantpressures. This is advantageous it flowmeter 700 is utilized in apipeline in which flows highly pressurized materials. Should flow tube101 rupture, the flowmeter housing is capable of containing thepressurized fluid. In the preferred embodiment of the present invention,housing cover 701 and housing base 450 are formed from steel by castingand provide secondary containment (rated to 500 pounds per square inch)for flowmeter 700. A feed-thru (not shown) is used to extend wiring frominside of flowmeter 700 to outside of flowmeter 700.

FIG. 8 depicts a flow chart illustrating the steps for the preferredmethod of fabricating the flowmeter of the present invention. Theassembly process begins with element 802. During step 804 the brace barhalves are threaded onto the flow tube. The flow tube may already havebeen partially or completely bent prior to threading the brace barhalves onto the flow tube.

Once the brace bar halves are threaded on the flow tube the adapters areattached to the inlet and outlet of the flow tube during step 806.During step 808 the flow tube inlet and outlet and attached adapters arebent, if necessary to achieve the final configuration of the flow tube.In the preferred embodiment, the flow tube inlet and outlet are in-linewith one another and in-line with the pipeline to which the flowmeter isattached. Therefore during step 808 the flow tube inlet and outlet arebent so that the adapters are in-line.

During step 810 the brace bar half pairs are welded to form solid bracebars. The solid brace bars can also be welded to the flow tube duringthis step or, alternatively, the brace bars are brazed to the flow tubeduring step 812.

A brazing operation is preferably performed during step 812. All theremaining necessary attachments to the flow tube are made during thisstep. This includes the anchor, brace bar brackets, pick-off sensorbrackets and driver attachments to the flow tube. Alternatively, onecould perform multiple welding operations to complete the necessaryattachments to the flow tube. The result of this step is a complete flowtube assembly. The flow tube assembly includes the flow tube andeverything in the completed flowmeter that is attached to the flow tubeincluding the anchor, brace bars, adapters, driver brackets and pick-offsensor brackets.

During step 814 the flow tube assembly is inserted into the housingbase. The anchor is then welded to the housing base. Any necessaryinternal wiring for the flowmeter is also completed during step 814.

During step 816 the flowmeter is completed by mating the housing coverto the housing base. The anchor is welded to the housing cover. Theadapters are welded to the housing base and the housing cover. Thehousing base and housing cover are welded around the entirecircumference of the housing to produce a housing providing secondarycontainment of pressure. Processing of the flowmeter then ends withelement 818.

Alternative Embodiments—FIGS. 5-6

FIG. 5 illustrates alternatively shaped flow tube 500. Flow tube 500 hasloops 501 and 502. Loops 501 and 502 are substantially B-shaped and areeach contained in respective parallel planes. Inlet 503 is connected toa pipeline (not shown) at one end and to loop 501 at its other end.Inlet 503 bends to direct the fluid flow from the plane of the pipelineto the plane of loop 501. The fluid flowing through loop 501 is directedto loop 502 through crossover section 605. Fluid is then directedthrough loop 502 where it is directed back to the plane of the pipelineby outlet 504. Flow tube 500 shares the crossover section design of theflow tubes described with respect to FIGS. 1-4.

FIG. 6 illustrates a second alternatively shaped flow tube 600. Loops601 and 602 are substantially circular and contained in respectiveparallel planes. Inlet 603 is connected to a pipeline (not shown) at oneend and to loop 601 at its other end. Fluid flowing through flow tube600 is directed from the plane of the pipeline to the plane of loop 601.The fluid then flows through loop 601 and is directed to loop 802through crossover section 605. The fluid then flows through loop 602.Outlet 504 then returns the flowing fluid to the pipeline plane fromplane of loop 152. Flow tube 600 shares the crossover section of thedesigns described with respect to FIGS. 1-5.

The present invention includes a dual loop, serial flow tube utilizing acomplex bend to direct flow from a first loop to a second loop. Thepresent invention also includes an anchor for securing the flow tube toa housing. The present invention includes a two-piece brace bar designand a method for assembling a flowmeter incorporating the features ofthe present invention. Although specific embodiments of the presentinvention are disclosed herein, it is expected that persons skilled inthe art can and will design alternative dual loop, serial flow tubeCoriolis flowmeters that are within the scope of the following claimeither literally or under the doctrine of equivalents.

What is claimed is:
 1. A Coriolis flowmeter assembly having a continuouslength of flow tube with dual loops, an inlet adapted to receive a flowof material from a connected pipeline and an outlet adapted to returnsaid flow of material to said pipeline and a housing enclosing said dualloops, said flowmeter assembly comprising: a first loop oriented in afirst plane in said continuous length of flow tube and having a firstend that receives said flow from said inlet and a second end; a secondloop oriented in a second plane in said continuous length of flow tubeand having a first end that receives flow from said second end of saidfirst loop and a second end directing said flow to said outlet; across-over section in said continuous length of flow tube formed by abend in said length of flow tube between said second end of said firstloop and said first end of said second loop, wherein said cross-oversection directs flow from said first loop to said second loop; bracebars connected to said first and second loops; and an anchor fixablyattached to said housing and to said continuous length of flow tubebetween said brace bars and said cross-over section.
 2. The Coriolisflowmeter assembly of claim 1 wherein said first plane and said secondplane are substantially parallel.
 3. The Coriolis flowmeter assembly ofclaim 1 wherein said first loop and said second loop are substantiallytriangular shaped.
 4. The Coriolis flowmeter assembly of claim 3 furthercomprising: a first angled section of said first loop between a firstsubstantially straight section and a second substantially straightsection of said first loop; a second angled section of said first loopbetween said second substantially straight section and a thirdsubstantially straight section of said first loop; a first angledsection of said second loop between a first substantially straightsection and a second substantially straight section of said second loop;and a second angled section of said second loop between said secondsubstantially straight section and a third substantially straightsection of said second loop.
 5. The Coriolis flowmeter assembly of claim4 wherein said first angled section and said second angled section ofsaid first loop and said second loop form substantially 45 degreecurvatures of said continuous length of flow tube.
 6. The Coriolisflowmeter assembly of claim 1 further comprising: a first adaptorfixably attached to said inlet of said continuous length of flow tubefor connecting said inlet to said housing and for extending a flow offluid from said pipeline to said inlet; and a second adaptor fixablyattached to said outlet of said continuous length of flow tube forconnecting said outlet to said housing and for extending a flow of fluidfrom said outlet to said pipeline.
 7. The Coriolis flowmeter assembly ofclaim 1 wherein said anchor comprises: an anchor base fixably attachedto said housing; a first end of said anchor base fixably attached to andformed to complement an outer diameter of said first end of said firstloop and an outer diameter of said first end of said second loop; asecond end of said anchor base fixably attached to and formed to receivean outer diameter of said second end of said first loop and an outerdiameter of said second end of said second loop; a first tube attachmentblock fixably attached to and formed to receive an outer diameter ofsaid first end of said first loop and an outer diameter of said firstend of said second loop, said first tube attachment block being fixablyattached to said first end of said anchor base to affix said anchor tosaid continuous length of flow tube; and a second tube attachment blockfixably attached to and formed to receive an outer diameter of saidsecond end of said first loop and an outer diameter of said second endof said second loop and, said second tube attachment block being fixablyattached to said second end of said anchor base to affix said anchor tosaid continuous length of flow tube.
 8. The Coriolis flowmeter assemblyof claim 1 wherein said housing comprises: a housing base fixablyattached to a first welded face of said anchor; and a housing coverfixably attached to a second welded face of said anchor and fixablyattached at its circumference to said housing base to form a sealedchamber within said housing.
 9. The Coriolis flowmeter assembly of claim8 wherein said housing base and said housing cover are formed to containa positive pressure when fixably attached together.
 10. The Coriolisflowmeter assembly of claim 1 wherein said anchor is formed from amaterial different than the material of said continuous length of flowtube.
 11. The Coriolis flowmeter of claim 1 wherein said first loop andsaid second loop project outward from a first surface of said anchorsaid continuos length of flow tube extends through said anchor betweensaid first and second loops and said cross-over section, and saidcross-over section of said continuous length of flow tube projectsoutward from a second surface of said anchor.
 12. The Coriolis flowmeterassembly of claim 1 wherein said first loop is oriented in a firstplane.
 13. The Coriolis flowmeter of claim 12 wherein said second loopis oriented in a second plane.
 14. A Coriolis flowmeter assembly havinga continuous length of flow tube with a first loop in a first plane anda second loop in a second plane, an inlet adapted to receive a flow ofmaterial from a connected pipeline and an outlet adapted to return saidflow of material to said pipeline, a driver affixed to said first loopand said second loop to oscillate said first loop and said second loopin opposing direction, pick-off sensors affixed to said first loop andsaid second loop to measure said oscillation of said flow tube and ahousing enclosing said first loop and said second loop, said flowmeterassembly comprising: a cross-over section in said continuous length offlow tube formed by a bend in said length of flow tube between a secondend of said first loop and a first end of said second loop, wherein saidcross-over section directs flow from said first loop to said secondloop; brace bars connected to said first and second loops; and an anchorfixably attached to said housing and to said continuous length of flowtube between said brace bars and said cross-over section wherein saidfirst loop and said second loop project outward from a first surface ofsaid anchor said continuos length of flow tube extends through saidanchor between said first and second loops and said cross-over section,and said cross-over section of said continuous length of flow tubeprojects outward from a second surface of said anchor.
 15. The Coriolisflowmeter of claim 11 wherein said first plane and said second plane aresubstantially parallel.
 16. The Coriolis flowmeter of claim 11 whereinsaid first loop and said second loop are substantially triangularshaped.
 17. The Coriolis flowmeter of claim 16 further comprising: afirst angled section of said first loop between a first substantiallystraight section and a second substantially straight section of saidfirst loop; a second angled section of said first loop between saidsecond substantially straight section and a third substantially straightsection of said first loop; a first angled section of said second loopbetween a first substantially straight section and a secondsubstantially straight section of said second loop; and a second angledsection of said second loop between said second substantially straightsection and a third substantially straight section of said second loop.18. The Coriolis flowmeter of claim 17 wherein said first angled sectionand said second angled section of said first loop and said second loopform substantially 45 degree curvatures of said continuous length offlow tube.
 19. The Coriolis flowmeter assembly of claim 11 furthercomprising: a first adaptor fixably attached to said inlet of saidcontinuous length of flow tube for connecting said inlet to said housingand for receiving a flow of fluid from said pipeline to said inlet; anda second adaptor fixably attached to said outlet of said continuouslength of flow tube for connecting said outlet to said housing and fordelivering a flow of fluid from said outlet to said pipeline.
 20. TheCoriolis flowmeter of claim 11 wherein said anchor comprises: an anchorbase fixably attached to said housing; a first end of said anchor basefixably attached to and formed to complement an outer diameter of saidfirst end of said first loop and an outer diameter of said first end ofsaid second loop; a second end of said anchor base fixably attached toand formed to complement an outer diameter of said second end of saidfirst loop and an outer diameter of said second end of said second loop;a first tube attachment block fixably attached to and formed tocomplement an outer diameter of said first end of said first loop and anouter diameter of said first end of said second loop, said first tubeattachment block being fixably attached to said first end of said anchorbase to affix said anchor to said continuous length of flow tube; and asecond tube attachment block fixably attached to and formed tocomplement an outer diameter of said second end of said first loop andan outer diameter of said second end of said second loop and, saidsecond tube attachment block being fixably attached to said second endof said anchor base to affix said anchor to said continuous length offlow tube.
 21. The Coriolis flowmeter of claim 11 wherein said housingcomprises: a housing base fixably attached to a first welded face ofsaid anchor (601); and a housing cover fixably attached to a secondwelded face of said anchor and fixably attached at its circumference tosaid housing bass to form a sealed chamber within said housing.